#bft #libra #reproducible-builds

bin+lib synchronicity

Distributed build system providing cryptographic proofs-of-reproducibility via Byzantine Fault Tolerant (BFT) consensus

1 unstable release

✓ Uses Rust 2018 edition

0.0.1 Nov 27, 2019
0.0.0 Nov 27, 2019

#4 in #bft

Apache-2.0 and MPL-2.0 licenses

161 lines

Synchronicity iqlusion

Build Status Safety Dance MSRV Apache 2.0 Licensed Gitter Chat

A connecting principle linked to the invisible.
Almost imperceptible. Something inexpressible.

—The Police, Synchronicity I

Distributed build system providing cryptographic proofs-of-reproducibility via Byzantine Fault Tolerant (BFT) consensus.



Synchronicity is a distributed build system for Rust crates which have been published to crates.io. It builds crates reproducibly inside of Docker containers managed using Rustwide, the core library behind tools like Crater and docs.rs.

Builders running Synchronicity also run a BFT consensus algorithm between each other (as part of a closed, "permissioned" group), and in doing so come to agreement on whether or not a build was successfully reproduced by a threshold of the group. Consensus is provided by Libra's HotStuff BFT.

Any builder can submit a build to be run by the rest of the group. The results of the build are then published as part of a commit-and-reveal scheme. After all builders have completed the build, or a timeout is reached, the builders reveal hashes identifying the build artifacts, and if a threshold of them match, evidence thereof is stored in an append-only Merkle log generated by the consensus group.

Once evidence of a successful build reproduction has been published in the log, clients interested in determining if they should trust a particular build can request cryptographic proof-of-inclusion that it has been successfully reproduced. So long as a threshold of the group does not collude to publish fraudulent reproducibility results, this cryptographic proof can be trusted as evidence that a build with a matching hash is reproducible from the original source code published on crates.io.


Synchronicity is a work-in-progress and at an early stage of development and is not ready to be used. Check back later!

Minimum Supported Rust Version

  • Rust 1.39+

Code of Conduct

We abide by the Contributor Covenant and ask that you do as well.

For more information, please see CODE_OF_CONDUCT.md.


Copyright © 2019 iqlusion

Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with the License. You may obtain a copy of the License at


Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language governing permissions and limitations under the License.


Unless you explicitly state otherwise, any contribution intentionally submitted for inclusion in the work by you shall be licensed as above, without any additional terms or conditions.


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